


Immunology

by Saki101



Series: Other Experiments [14]
Category: Sherlock (TV), Sherlock Holmes & Related Fandoms
Genre: Alternate Reality, Alternate Universe, Episode Related, M/M, Post Reichenbach, The Great Game
Language: English
Status: Completed
Published: 2012-03-04
Updated: 2012-03-04
Packaged: 2017-11-01 03:33:01
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,533
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/351512
Author URL: https://archiveofourown.org/users/Saki101/pseuds/Saki101
Summary: <blockquote class="userstuff">
              <p>The experiment took a turn Sherlock had not expected.</p><p>Excerpt:  John had done battle and triumphed.  He just didn’t know it yet.</p>
            </blockquote>





	Immunology

**Author's Note:**

> This is a continuation of the [Other Experiments](http://archiveofourown.org/series/15644) series which forms an AU frame for the [Experiments](http://archiveofourown.org/series/15016) series. _Immunology_ is set after [Silk Road](http://archiveofourown.org/works/619337).

John had done battle and triumphed. He just didn’t know it yet. 

When John touched the tombstone, Sherlock took a deep breath of the John-laced air. Even from the distance from which he watched, it smelt smoky. The same charred tinge had surrounded John the day they met, and when John awoke from nightmares the singed aroma curled down the stairs and into the sitting room. The first night, Sherlock had scaled the steps two at a time to extinguish the flames, realising only at John’s door that this fire required that John come to him. It had not been easy to wait.

Sherlock blinked slowly, sliding the image of John’s hand reaching towards the dark stone into a safe place in his mind, drawing in more of John’s scent before it faded as John walked away. This time John would have to wait. There was so much that needed to be done before Sherlock could tell John about the battle they had won. Sherlock turned. His muscles ached, his blood still burned faintly in his veins. The struggle had taken days, but Moriarty had never reached the heart he had promised to burn out. It had stubbornly pumped through the agony and the fever as John fought Moriarty from cell to cell inside Sherlock. 

********** 

Molly almost ran to Mike’s office. Mike was taking his jacket off when she leaned around the open door and gasped, “Where's your phone? He’s asking for you.”

“Bad?” Mike shoved his arms back in the sleeves and was locking the office door behind him in a moment. He pulled his mobile out of his jacket pocket as he followed Molly, turned the blank, open screen towards her and shook his head apologetically.

“He wouldn’t let me get close, but I could see the fever’s back,” Molly replied. They had taken the stairs instead of the elevator to the library. “It was probably too soon for him to do that much.”

“Let’s hope it’s only that,” Mike said, punching in the door code to the Rare Books Room. He and Molly slipped inside and closed the door behind them before reaching for the light switch.

************ 

The fever brought Sherlock’s memories to vivid life. His brain seemed to have favourites. 

The sun had been bright on the roof. Barts was Sherlock’s home territory, but even after a week snooping through its records Moriarty didn’t _appear_ to know that. Suggesting the roof dovetailed so well with his plan for a literal as well as a figurative fall, Sherlock hoped it would appeal. Moriarty had blind spots, at least when it came to Sherlock. He had surprised Moriarty at the pool, as had John. Moriarty should be more prepared this time. 

The escape plan was in place. Sherlock was so involved with the challenge of executing the trick that it took him a moment on the ledge to see the flaw in Moriarty’s design. Sherlock laughed when he spotted it and Moriarty growled. Clearly, Moriarty was distracted, too. It was a strange oversight for them both.

It lured Moriarty back. “What? What did I miss?” he spat, furious and excited. Who else could have found something that he might have missed?

Sherlock circled and laughed, nearly sang with the simplicity of it. Moriarty didn’t like the idea that he could be manipulated, that he’d given his weakness so blatantly away. He had taunted John for tipping his hand. Well, Moriarty had tipped his. He was at war with himself, the desire to win almost outstripped by the desire to play. Their little game had meant so much more to him than he wanted to admit, so much more than it could to Sherlock. Moriarty didn’t have a John Watson.

Sherlock played Moriarty, standing close, using every centimetre of his height, every gram of his weight, every tone of his voice to work the effect he wanted to have. Sherlock selected his words as he would weapons. He polished each one before deploying it, enunciating with a soft authority, his voice deep, his lips and tongue shaping each sound voluptuously. He reared above Moriarty like a cobra, the sunlight an aura round his head. Moriarty was being drawn, his mind, his pride struggling against the gravity of Sherlock letting just a little of what he was show, most assuredly not an angel. Moriarty touched Sherlock’s sleeves, stroked them. Sherlock had felt Moriarty floundering. Or had he? 

“No, you’re me. You’re me. Thank you, Sherlock Holmes,” Moriarty had said, his voice high, unstable. Unexpectedly, he held out his hand. 

Sherlock thought the contact would draw Moriarty in even more securely as he clasped it. Sherlock’s palm prickled and something in Moriarty changed. 

“Well, good luck with that,” Moriarty sneered. The gun had been a surprise, too, where he aimed it even more so. Sherlock broke away, stepped back before the gun fired, the flesh of his hand tingling.

The disorientation had been profound. Moriarty’s shattered skull spewing blood over the rooftop had done much more than foil Sherlock’s first solution to the threat of the gunmen. Sherlock’s arm was burning up to the elbow and he didn't have time for pain. It was making thinking difficult. The escape plan would still remove the threat to his friends, to John. Sherlock positioned his feet on the ledge, looked down into the street, forcing his mind to review the distances, the angles. Normally, confident in his physical skills and his calculations, the challenge of executing the fall would have made Sherlock smile, but the experience of having been wrong altered his perspective. He hated missing something just as much as Moriarty had. The pain moving up to Sherlock’s shoulder was distracting. He needed John’s voice to ground him before he jumped. It was both harder and easier to see John getting out of a taxi as he answered the call. Sherlock hoped that what Moriarty had done to him couldn’t affect John without a touch.

“I can’t come down,” Sherlock said and reached out with his other hand, the uncontaminated one. The pain was inching across his chest. Moriarty had said he would burn the heart out of him. An attempt at fusion had not remotely occurred to Sherlock. He didn’t think it had ever been done. Fusion was possible with some humans. Once fused, it was known that they could mate with one another, as Sherlock’s parents had done, or with other humans. There was no information on fusing as humans. He should have thought of it though. Moriarty’s attraction was clear enough, but Sherlock hadn’t responded to Moriarty’s human approach. It had been clumsy, repellent. Once he’d known that Jim from IT was Moriarty, he had assumed it had been a cover to observe at close range. Clearly, it had been more. _Interesting._ He couldn’t help thinking it even as he winced from the assault. Salt water trickled down Sherlock’s face. This was going to hurt John even if the escape jump succeeded because Sherlock wasn’t sure he was going to live through what Moriarty had done to him or what he would be, if he did. If it was what he feared, he might not ever be able to go back to John. Sherlock tossed away his phone, poised as for a dive and flew as close to John as he could.

********** 

“Off!” Sherlock’s voice rose from the far side of the room. “It hurts my eyes.” 

Molly obeyed before Mike located the source of the voice. He waited impatiently for his vision to adjust to the dim light from the windows high in the rotunda of the book-lined room. Then he saw the dark mound on the farthest reading table.

“Mask, gloves,” Sherlock ordered before Mike could take a step towards him. 

Mike could hear the tightness in Sherlock’s voice. 

“Molly, leave. You’re more susceptible,” Sherlock added, his jaw clenched around the words.

Molly nodded at Mike, pulled a mask and gloves out of her lab coat pocket, handed them over and let herself out.

Mike listened to the door click shut before he made his way between the tables to where Sherlock was hunched over the table, his head buried in his arms. He hadn’t taken his coat off.

“Molly said you’re feverish. How high?” 

“Forty,” Sherlock murmured. “It took forever from Highgate.”

Mike drew in a breath. “That’s a set-back, then,” he said and took the empty glass near Sherlock’s elbow and opened the door to the next room. 

“That hurts, too,” Sherlock commented.

“The sound of the water running?” Mike asked as he walked back to Sherlock with a full glass. “Drink.”

Sherlock lifted his head high enough to do so, then let it fall back on his arms, his hand still around the empty glass. Mike took it back and re-filled it.

“What have you taken?” Mike asked, setting the water glass on the table.

“Nothing yet,” Sherlock replied.

“Cause?”

“Exposure to John is the main factor, but exertion is playing a role. I could smell him,” Sherlock said. “Take a blood sample.” Sherlock dragged himself off the table and Mike helped him pull his arms out of his coat sleeves. “He was close enough to smell me, then,” Sherlock added. “Although he might not have been aware of it. Call him. If he doesn’t answer, call Mrs Hudson. If she doesn’t answer, go round. We don’t know whether I’m contagious.”

“John first?” Mike asked, his hand hovering over the cuff of Sherlock’s shirt.

“John first,” Sherlock affirmed.

************* 

Sherlock opened his eyes. They didn’t ache. He thought that a good sign, but he didn’t move yet. 

His blood had confirmed his diagnosis, some of Moriarty’s cells had remained in his system. In each slide Mike had prepared, neutrophils were swarming over the one or two blood-like cells which were not Sherlock’s. _John’s neutrophils._ Sherlock was not given to anthropomorphising microbiological processes, but fury had seemed the only word to describe the speed at which the neutrophils had been devouring Moriarty’s cells. As it had been in the first forty-eight hours after Moriarty had grasped his hand, Sherlock’s immune response had been inactive. 

Sherlock had wanted to study the slides longer, but he hadn’t been able to stay upright. Mike had helped him to bed before he left to check on John in person. If Sherlock had inhaled enough of John to trigger this reaction, John might have been infected by the trace of Moriarty Sherlock must have been exhaling.

Staring up into the darkness, Sherlock catalogued his condition. His temperature was definitely lower, but he wasn’t sure it had returned to what was normal for him. He would have to check it when he got up. He took a deep breath. His lungs seemed clear, his chest ached only slightly as it rose and fell. The air didn’t smell of John. Sherlock hadn’t anticipated that separation would be so physically difficult. Perhaps it wouldn't have been without Moriarty's final barb. The mechanics of that made sense. If one's fusion partner were no longer present, one was apparently able to fuse with another. If the current partnership were active, an attempt at another fusion would be fought off like an infection. _Elegant._

He tried to reach his phone on the night table, but his body wasn’t responding well to commands. His hand fell limp at the edge of the bed. 

Sherlock recalled staring up at another ceiling, sprawled in his chair, gun dangling from his hand, the tingly feeling creeping through his veins making his whole body want to fly apart. He hated it when John went out and shooting at the wall had not helped. He had leapt up when he heard John coming in, aimed at the smiley face from behind his back as John walked in. John had taken the gun away. It felt better when John was near, better still when he touched. He didn’t do that often enough.

That day Sherlock had been tempted to say, at least to himself, that it had been a mistake to call out and a mistake to continue the experiment when John appeared to answer his call.

Sherlock stretched again until his fingertips reached the night table, scrabbled along the surface until he found his phone. He needed to see if Mike had sent a message about John. And he needed something that smelled of John since John himself wasn’t something he could have. The small screen lit Sherlock’s face. No messages. He noted the time, he had slept for hours. Mike would have texted if John’s condition were critical. Sherlock began a text, hoped Mike was still at the flat, wasn’t sure what excuse Mike could use to acquire what was needed. Sherlock added another line: Try clothes hamper in the loo. His hand dropped to the bed, sliding the phone shut. The small light winked out. Texting had drained him.

He had felt tired that other day, too, exhausted and restless at the same time. When John had gone back out, Sherlock had been shocked. He had picked himself off the sofa and watched John cross the road. He hadn’t understood how John could leave. Whatever the process was, it was working faster on Sherlock than on John. He didn’t feel separation the way Sherlock did.

The phone was smooth in the palm of his hand. His fingers stroked back and forth over the casing. It had been such an effective way to summon John. Sherlock smiled in the dark, his other hand smoothing down his vest. There had been no sense of waiting then. _I’d be lost in my thoughts until you drew me away from them with your arrival._ Sherlock sat up.

“Things changed,” Sherlock whispered. “The agitation. Not lack of nicotine or caffeine. Not boredom either.” Sherlock sagged back against the pillows. _It was a lack of you that made it hard to think. And I’m nothing without my thoughts._ Sherlock rubbed a hand over his face. His eyes were stinging again. _I tried to explain about my brain rotting, but that wasn’t the problem, was it? That’s what it always was before you and working on a case almost always solved it._ Sherlock rolled onto his side, pressed his face into the pillows, pulling the phone against his chest. _I couldn’t believe you walked back out that day. I wonder if Moriarty knew. When the windows exploded, it was a relief._

********** 

“Did you sleep all night?” Mike asked when Sherlock rolled onto his back and opened his eyes.

Sherlock stretched, twisting his neck from side to side, his fingers brushing against the wall above the headboard, his feet bumping into the footboard. The phone was still in one hand. “It would appear so. How is John?”

Mike’s eyes crinkled over his mask. “Fine. He was feverish last night. I persuaded him to go to bed early.” Mike pressed a thermometer into Sherlock’s ear. “He came out of the bathroom wearing your pyjama bottoms. I pretended not to notice the rolled up cuffs.” Mike drew the thermometer out. “I also convinced him to sleep in your room, so I could sleep on the couch and hear him if he needed anything. I told him there was a flu going round among the students. The fever was gone this morning.” Mike held the thermometer up. “And so is yours.” 

“He wasn’t suspicious that you offered to stay the night?” Sherlock asked, looking around the room.

“Compared to your reaction, his was mild, but he was dizzy and achy enough to realise that it might get considerably worse,” Mike said. “And I think he appreciated the company. I told him Aditha’d taken the children to her mother’s again this weekend.” Mike followed Sherlock’s gaze to the chair where Mike had left his coat. “I brought you this,” Mike added, stepping away to grab his coat. He reached into the inside pocket and pulled out John’s striped jersey.

Sherlock smiled as he extended his hand. “John’s going to miss that,” he said.

“I was wondering if my company was particularly acceptable because I must have smelled of you,” Mike replied. “I think he’ll continue sleeping in your room now that he’s tried it. He looked better this morning than he’s looked since…well…even despite the fever.” 

“There are so many things I have to do, Mike,” Sherlock said, before lifting John’s garment to his face and inhaling. Sherlock closed his eyes for a moment before letting his hand drop. “I need to get my strength back. All of it.”

“We’ll check your blood again. See if the immune response has died down. My guess is that it has. Oh, I got John to agree to give a sample as well. Two, actually. One last night and another this morning,” Mike explained, pulling the small vials out of his other coat pocket. “We may be about to verify at least one physical effect of fusion.”

“I should have been taking blood samples from the first day. My own at least,” Sherlock said. “It never occurred to me.”

“Well, you can’t think of everything,” Mike said. Sherlock drew back, his eyes opened wide. “Sorry,” Mike added quickly. 

*********** 

“I appreciate that you didn’t cancel,” Mike said to John when the students had dispersed. His voice echoed slightly in the empty hall. 

John leaned against the table to the side of the podium, his hand running absently back and forth along the wood. “Their questions were good. I can cover those topics in more detail in the next lecture,” John replied. He pressed his palm against the table and scanned the room. “Strange to think that we sat in these same seats all those years ago.”

Mike sat down in a first row seat and stretched his legs out in front of him. If John wasn’t eager to leave the room, he wasn’t going to rush him. “It seems odd to be walking up to the podium sometimes,” Mike remarked. “I expect to see Wallace blustering or Anderson sliding up and down the wall doing his callisthenics.” 

John chuckled and slid back to sit on the table. “Remember the impressions Stranahan could do of them?” 

“And the day the dean came in behind him? We thought Stranahan was going to be expelled and then Yoda laughed. I never thought I'd see that.”

“None of us knew what to do. We didn’t dare laugh, too. I thought I was going to choke,” John said, smiling and shaking his head.

Mike noted that John had both of his hands flat on the table on either side of his legs now.

“Want to come over for dinner? Meet Aditha and the twins?” Mike asked.

“Another time, I hope,” John replied, sliding forward on the table. “I’ve got a morning shift tomorrow.” Mike quirked an eyebrow. “Remember Sarah?” 

Mike tilted his head. “Has a clinic?” 

“That’s her. One of her staff recently returned from maternity leave and wants to drop down to part time. Sarah asked if I’d take the other half for six months,” John replied, taking a deep breath.

“Will you?” Mike asked. 

“I’m shadowing Stine this week, getting to know some of her patients. If it goes well, I’ll take the afternoons from next week,” John said. “My first reflex was to say no, but it’ll be a help to them both.” John stood up, one hand still resting on the table behind him.

“Will you be able to make the next lecture, then?” Mike asked, standing.

“I get benefits as well. Imagine, paid holiday time, personal days. I can use some for the lectures or maybe swap shifts with Stine.”

Mike resisted the urge to clap John on the back. “So just a quick stop at the lab to draw a little blood, then?”

John finally stepped away from the table. “Vampire.” 

“Come on, it’s a tiny sample,” Mike said. “Mind, you don’t have to wait until your next lecture to take up the dinner invitation.”

“I suppose a home-cooked meal is worth a little blood,” John said, nodding.

*********** 

Sherlock looked over the computer monitor when Mike stuck his head around the door. Sherlock had followed one hacking attempt back to the Bank of England, thought it could well be the same person who had given Moriarty a hand with that part of his grand crime. 

The fever had not returned, but Sherlock was still the colour of paper, Mike observed. “John’s just left. Go on down. If you don’t need me for anything else, I’m heading home.”

“How was he?” Sherlock asked, pushing back from the desk.

“Not bad. Better by the end of the lecture. He was practically petting the table where you had been sitting,” Mike added. “The cleaners come through there around nine.”

“See you tomorrow, then,” Sherlock said. He didn’t follow Mike out into the main library. The rollers on the bookcase squeaked a little as Sherlock slid it aside to reveal the spiral stairs leading down to the lecture hall.

********** 

Sherlock had locked all the entrances to the lecture hall before he stretched out on the table on the dais. He pressed his cheek to the cool wood and closed his eyes.


End file.
